Abstract
This Letter reports the first scientific results from the observation of antineutrinos emitted by fission products of U235 at the High Flux Isotope Reactor. PROSPECT, the Precision Reactor Oscillation and Spectrum Experiment, consists of a segmented 4 ton Li6-doped liquid scintillator detector covering a baseline range of 7-9 m from the reactor and operating under less than 1 m water equivalent overburden. Data collected during 33 live days of reactor operation at a nominal power of 85 MW yield a detection of 25 461±283 (stat) inverse beta decays. Observation of reactor antineutrinos can be achieved in PROSPECT at 5σ statistical significance within 2 h of on-surface reactor-on data taking. A reactor model independent analysis of the inverse beta decay prompt energy spectrum as a function of baseline constrains significant portions of the previously allowed sterile neutrino oscillation parameter space at 95% confidence level and disfavors the best fit of the reactor antineutrino anomaly at 2.2σ confidence level.
| Original language | English |
|---|---|
| Article number | 251802 |
| Journal | Physical Review Letters |
| Volume | 121 |
| Issue number | 25 |
| DOIs | |
| State | Published - Dec 19 2018 |
Funding
This material is based upon work supported by the following sources: U.S. Department of Energy (DOE) Office of Science, Office of High Energy Physics under Awards No. DE-SC0016357 and No. DE-SC0017660 to Yale University, under Award No. DE-SC0017815 to Drexel University, under Award No. DE-SC0008347 to Illinois Institute of Technology, under Award No. DE-SC0016060 to Temple University, under Contract No. DE-SC0012704 to Brookhaven National Laboratory, and under Work Proposal No. SCW1504 to Lawrence Livermore National Laboratory. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344 and by Oak Ridge National Laboratory under Contract No. DE-AC05-00OR22725. Additional funding for the experiment was provided by the Heising-Simons Foundation under Award No. 2016-117 to Yale University. J. G. is supported through the NSF Graduate Research Fellowship Program and A. C. performed work under appointment to the Nuclear Nonproliferation International Safeguards Fellowship Program sponsored by the National Nuclear Security Administrations Office of International Nuclear Safeguards (NA-241). This work was also supported by the Canada First Research Excellence Fund (CFREF), and the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery program under Grant No. RGPIN-418579, and Province of Ontario. We further acknowledge support from Yale University, the Illinois Institute of Technology, Temple University, Brookhaven National Laboratory, the Lawrence Livermore National Laboratory LDRD program, the National Institute of Standards and Technology, and Oak Ridge National Laboratory. We gratefully acknowledge the support and hospitality of the High Flux Isotope Reactor and Oak Ridge National Laboratory, managed by UT-Battelle for the U.S. Department of Energy.
| Funders | Funder number |
|---|---|
| National Nuclear Security Administrations Office of International Nuclear Safeguards | NA-241 |
| UT-Battelle | |
| National Science Foundation | |
| U.S. Department of Energy | |
| National Institute of Standards and Technology | |
| Yale University | |
| Office of Science | |
| High Energy Physics | DE-SC0016060, DE-SC0016357 |
| Lawrence Livermore National Laboratory | DE-AC52-07NA27344 |
| Oak Ridge National Laboratory | |
| Brookhaven National Laboratory | |
| Temple University | |
| Illinois Institute of Technology | |
| Heising-Simons Foundation | 2016-117 |
| Natural Sciences and Engineering Research Council of Canada | |
| Canada First Research Excellence Fund |